Cyclic alcohols and esters and preparation thereof



United States, PatefltO CYCLIC ALCOHOLS AND ESTERS PREPARATION THEREOF No Drawing. Application March 5, 1958 Serial No. 719,454

17 Claims. (Cl. 260-488) Thisinvention relates to novel chemical compounds and to novel methods of making the same. More particularly, the invention relates to novel chemical compounds, having odorant properties, which compounds can be characterized broadly as: 4-[2-methyl-5-(secondary acyclic hydrocarbyl)-1-cyclopenten-l-yl (and -cyclopentan-1-yl)]-2-butanols; nuclear lower hydrocarbyl-substituted analogs thereof; and certain esters of all of the foregoing alcohols. The invention relates further to methods of preparing said alcohols from 4-[2-methyl-5-(secondary acyclic hydrocarbyl)-1-cyclopenten-1-yl (and -cyclopentan-l-yl)]-2-butanones and analogs; and to methods of preparing said esters from said alcohols.

The novel compounds of the invention are more precisely defined by the followinggeneral formula:

The symbol X represents'a tetravalent radicalselected from the group consisting of the radical =CH.CH=

and the radical =C=C=; the symbol Y represents 'a member selected from the group consisting of lower alkyl radicals and lower alkenyl radicals each containing at least three carbon atoms and attachedthrough the 2 carbon atom thereof; the symbol Z represents a member selected from the group consisting of hydrogen and hydrocarbyl carbonyl radicals which contain inthe hydrocarbyl portion thereof not more than seven carbon atoms; and each of the symbols R, R and R" represents a member selected from the group consisting of hydrogen and lower acyclic hydrocarbon radicals;-it being understood that the three symbols R, R and R can, but need not, be identical.

In the above Formula I, illustrative meanings of the symbol Y include: methyl, ethyl, isobutyl, tert. butyl, ethylidene, isobutylidene, n-pentylidene and the like. Illustrative meanings of the symbol Zinclude: hydrogen;

4 (2,5 dimethyl 5 -isopropeny1- 1 cyclopenten l yl) 2 butanone;

4 [2 methyl 5 (2 buten 2 yl) 1 cyclopenten 1 -yl] 2 butanone;

4 [2 methyl 5 (4 methyl 2 penten 2 yl)-1 cyclopenten 1 yl] 2 butanone;

4 (2 methyl 3 ethyl 5 -.isopropenyl 1 cyclopenten 1 yl) 2 butanone;

4 (2 methyl 3 allyl 5 isopropenyl 1 cyclopenten 1 yl) 2 -butanone; v

4 (2 methyl 3 propargyl 5 isopropenyl 1 cyclopenten 1 -,yl) 2 butanone; p

4- [Z-methyl- 3-ethyl-5- (2-buten-2-yl) 1 cyclopenten 1 yl] 2 butanone;

4- [2-methyl- 3-allyl-5-(2-buten-2-yl)-1- cyclopenten l yl] 2 butanone; x

4 (2 methyl 5 isopropyl 1 cyclopenten 1 yl) 2 butanone; I

4- (2,5 dimethyl 5 -isopropyl 1 cyclopenten l .yl) 2 butanone;

4 (2 e methyl 5 sec.-.butyl -'1 cyclopenten 1 yl) 2 butanone; t r

4 (2 methyl 3 ethyl 5 isopropyl l cyclopenten a 1 yl) 2 butanone; 4 (2 methyl 3 propyl 5 isopropyl 1 cyclopenten 1 yl) 2 butanone; 4 (2 '1 methyl 5 isopropyl 1 cyclopentyl) 2 *butanone; 4 q (2,5 dimethyl 5 isopropyl 1 cyclopentyl) 2 butanone; p 4 (2'- methyl 5 sec.-butyl 1 cyclopentyl) 2 butanone; I e r 4 (2 methyl 3 ethyl 5risopropyl- 1 cyclopentyl) 2 butanone; 4 (2 methyl 3 propyl 5' isopropyl 1 cyclopentyl) 2 butanone; and 4 (2 methyl 3 propyl 5' pentyl) 2 butanone.

- see.-butyl 1 cyclo- The invention provides two general methods of making compounds included within the above Formula I. The first general method comprises reducing the starting material by the Meerwein-Ponndorf-Verley reaction: e.g. by heating the starting material with a mixture of an aluminumtriUower alkoxide) and a lower, alkanol. Inpracticing this methodof the invention, it is preferred to use a mixtureof aluminum tri(isopropo1 iide) and isoprolower alkanoyl, such as formyl, acetyl, propionyl, isobutyryl, caproyl; cycloaliphatic acyl, such as cyclohexylcarbonyl, cyclohexylacetyl; aroyl, e.g. benzoyl, p-toluoyl, o-toluoyl; and the like. Illustrative meanings of the symbols R, R and R include: hydrogen; lower alkyl, such as methyl, ethyl, isopropyl; lower alkenyl, such as allyl;

lower alkinyl, such as propargyl; and the like; it being.

ing materials include: g r 4 -"(2 methyl 5 isopropenyl l cyclopenten 1 -.yl) I 2 butanone;

panol as the reducing agent mixture.- This first method of preparation results in the reduction of the oxo unsaturat ion only, leaving unchanged any side chain unsaturationand any nuclear unsaturation which may be present in the starting material.

f A second: general method of preparation provided .by the invention comprises catalytically hydrogenating the starting material in the presence of a Raney nickel hydrogenation catalyst. When the hydrogenation is conducted under mild reaction conditions, i.e. at room temperature and; under substantially atmospheric or only slightly superatmospheric hydrogenation pressures, only the oxo unsaturation, and the side chain unsaturation (when present), in the starting material is reduced. When the hydrogenation is conducted under more severe reaction conditions, e.g. at a reaction temperature of about C; and under a hydrogen pressure of about 500 p.s.i. gauge, all unsaturation in the starting material--i.e. in theoxo group, in the side chain (when unsaturation is present) and in the nucleus (when unsaturation is present)-is reduced. V

It will be understood from the foregoing that when a starting material "of the class 4-[2-methyl-5-(2-lower alken-2-yl)-1-cyclopenten-l-yl]-2-butanone is reduced by means of a mixture of a lower alkanol and an aluminum tri(lower alkoxide), the product is a 4-[2-methyl-S-(2- lower-alken-2-yl)-1-cyclopenten-1-yl]-2-butanol. When a starting material of the class 4-[2-me'thyl-5-(2-lower alkyl)-1-cyclopenten-1 yl]-2-butanone is reduced by means of a. mixture ofa lower; alkanol and" an; aluminum tri(lower alkoxide), the product is a4-[2-methyl-5-(2- loweralkyl)-1-cyclopenten-1-yl]-2-butanol. When a starting material of the class 4-'[2-methyl-5-(2-lower alkyl)-1.-cyclopentyl]-2-butanone is reduced by means of a mixture of a lower alkanol and an aluminum tri(lower alkoxide), the product is a 4- [-2-methyl-5-(2-lower alkyl)- l-cyclopentyl]-2-butanol.

Similarly, it will be understood that when astarting material either of the class 4- [2-methyl-5-(2-lower alken- 2-yl)-l-cyclopenten-l-yl'l-2-butanone or of the class 4- [2-methyl-5-(2-lower alkyl)-1-cyclopenten-l-ylZl-2 butanone isreduced bycatalytic hydrogenation in'the-presence of Raney nickel under mild reaction conditions, for example at roomtemperature and at a very slight superatmospheric hydrogen pressure, the product is, in each instance, a 4-[2-methyl-5-(2-lower alkyl)-l-cyclopentenl-yll-2-butanol. When a starting material of; the jclass4- [2-methyl-5-(2-1ower alkyl) -1-cyclopentyl] -2-butanone is reduced by catalytic hydrogenation in the presence of Raney nickel under mild reaction conditions, for example those stated in the preceding sentence, the product is a 4- [2-methyla5- (2-lower alkyl)-1-cyclopentyl1-2-butanol; However, when reducing catalyticallyin the presence of a Raney nickel catalyst and employing severe reaction conditions, for example when catalytically'hydrogenating in-the presence of Raney nickel at 125 C. under a hydrogen pressure of 500 p.s.i. gauge, the product is a t-[2- methyl-S-(Z-lower alkyl)-1-cyclopentyl]-2-butanol, irrespective of whether the starting material is a 4- lZZ-methyl- S-(2-lower alken-2-yl)-1-cyclopenten-1-yl]-2-butanone or a 4-[2-methyl-5-(2-lower alkyl)-1-cyclopenten-1-yl]-2- butanone or" a- 4-[2-methyl-5-(2-1ower alkyl)-l"-cyc lopentyl]-2-butanone.

One preferred embodiment of the invention relates to compounds defined by the following general formula:

(H) OH; CH-T HCg--I-C-CHz CHr-?H-CHa o, z H04 20 -011- wherein the symbol T represents an alkyl radical having from one to four carbon atoms, and the symbol Z has the same meaning indicated above in connectionv with Formula I. Particularly preferred in this embodiment of the invention .are the compounds generically identified as 4- [2-methyl-5-( 2-lower alken-2-yl) -1-cyclopenten-l-yl]-2- butanol; especially 4-(2rmethyl-5-isopropenyhl-cyclopenten-l-yl)-2-hutanol. Also preferred are esters, of alcohols selected from the genus referred to in this paragraph with certain organic acids, said' acids containing not more than eight carbon atoms and consisting only of carbon, hydrogen and oxygen atoms, the only oxygen atoms presentbeingthose contained in the carboxyl' group of the acid. Particularly preferred in this category of esters are the compounds identified by the generic description 4,-[2-methyl-5-(2-lower alken-2-yl)-1-cyclopenten-l-ylJ-Z-butyl lower; alkanoate; especially 4-(2- methyl-S-isopropenyl-l-cyclopenten-1 yl)-2-butyl acetate,

Another preferred embodiment of the invention. relates to. compounds defined by the following general formula:

wherein the symbol T represents an alkyl radical having from one to fourcarbon atoms, and the symbol Z has the same meaning indicated; above in connection with Formula I. Particularly preferred in this embodiment of the invention are the compounds generically identified as 4-[2-methyl-5-(2-loweralkyl)-1-cyclopenten-l-yl]-2- butanol; especially 4-(2-methyl-5-isopropyl-l-cyclopentenl-yl)-2-butanoll Also preferred are esters of alcohols selected from the genus referred to in this paragraph with -certain organic acids, said acids containing not more than eight carbon atoms and consisting only of carbon, hydrogen and oxygen atoms, the only oxygen atoms present being those contained in the carboxyl group of the acid; Particularly.preferred-in this category of esters are the compounds identified by the generic description 4- [2-methyl-5- (2'-.lower' alkyl)-1=cyclopenten-1-yl] -2-butyl lower alkanoate; especially 4-(2-methyl-5-isopropyll-cyclopenten-1 yl)-2-butyl acetate.

Still another preferred: embodiment, of the invention relates to compounds defined by the following general formula:

wherein the symbol T represents an alkyl radical having from one to four carbon atoms, and the symbol Z has the same meaning indicated above in connection with Formula I. Particularly preferred in this embodiment of the invention are the compounds generically identified as 4-[2 methyl- 5 (2 lower alkyl)-l-cyclopentyl]-2 butanol; especially 4-(2-methyl-5-isopropyl-l-cyclopentyl)-2-butanol. Also preferred are esters of alcohols selected from the genus referred to in this paragraph with certain organic acids, said acids containing not more than eight carbon atomsand consisting only of carbon, hydrogen and oxygen atoms, the only oxygen atoms present being those contained in, the .carboxyl group of the acid. Particularly; preferred in this. category of esters are the compounds identified by thegeneric description 4-[2- methyl-5-(2-lower alkyl) -1-cyclopentyl]-2-butyl' lower alkanoate; especially 4-(2-methyl-5-isopropyl-l-cyclopentyl)-2-butyl acetate.

The invention also provides a, method of making the novel esters, previously described, which comprises esterifying-a novel alcoholof the invention with an esterification agent appropriate to introduce an acyl radical having not more than eight carbon. atoms. and containing only carbomhydrogen and oxygen atoms, oxygen being present only inthe acylating function. Any of the esterification methods known per secan be. employed, but it is usually preferred to react the alcohol withan acid chloride or acid anhydride (or mixture thereof) in the presence of a proton acceptor, e.g. a tertiaryorganic base.

The novel compounds of the invention described by Formula I above, including preferred embodiments of the invention described in connection with Formulas II, III and IVabove, areuseful as odor-imparting agents,

' e.g. in thepreparationof perfumes, soaps, pharmaceutical compositions and scented compositions generally. The compounds of the invention are characterized gen- .erallyasbaving odors of an ionone type, but with woody and earthy notes, Accordingly, they are especially usefulin the preparation of perfumes of the-character of cedar wood, sandalwood and; patchoulia Theinvention' is further disclosed in the following examples, which are illustrative but not limitative thereof. Temperatures are stated in degrees centigrade (uncorrected). e

.to complete elimination of acetone.

Example I The residue was allowed to cool, and was dissolved in a mixture of 245 cc. of-concentrated HCl and 1225 cc. of water. The oil was extracted with toluene, and the organic layer was separated and washed neutral. The solvent was removed in vacuo, and the product was isolated by vacuum distillation. 4-(2-methyl-5-isopropenyll-cyclopenten-l-yl)-2-butanol was obtained at 78-81 (0.25 mm.); 21 1.4856. d

Example 2 4 (2 methyl-S-isopropyl-l-cyclopenten-l-yl):Zibutanone (700 g.) was dissolved in methanol (1000cc.) and was hydrogenated in the presence .of Raney nickel "(100 g.) at atmospheric temperature and pressure. Absorption of hydrogen was 0.98 mol equivalents (98% of theory).

The catalyst was removed by filtration, and the. product was isolated by distillation. 4-(2-methyl-5-isopropyl-1- cyclopenten-l-yl)-2-butanol was obtained at 69-71 (0.25 mm.);n 1.4738. I I

Example 3 A solution of 4-(2-methyl-5 -isopropyl-1 -cyclopentyl)-2- butanone (506 g.) in methanol (500 cc.) was hydrogenated, in the presence of Raney nickel (100 g.), at atmospheric temperature and pressure, until there was no fur After filtration of the 'ther absorption of hydrogen. catalyst, the product was purified by vacuum distillation. 4-(2-methyl 5-isopropyl-l-cyclopentyl)-2-butanol was obtained at 8386 (0.8 mm.); 11 1.4581;

Example 4 g In the same manner described in Example 1*, a mixture of 4 (2,5-dimethyl-S-isopropenyl-l-cyclopenten l-yl)-2- butanone (133.5 g.), aluminum tri(isopr'opoxide) (132.3 g.-), and isopropanol (648 cc.) was heated to reflux. Acetone was removed from the head of the column until the vapor temperature reached 82. Then excess isopropanol was rapidly removed in vacuo. The residuelonger observed in the distillate. The reaction mixture was worked up as described in Example 1, yielding 4- (2,5 dimethyl-S-isopropyl-l-cyclopentyl)-2-butanol of B.P. 8586 (0.6 mm.) and n 1,4729.

Example 6 c A mixture of 4-(2-methyl-3-ethyl-5-isopropenyl-1-cyclopenten-l-yl)-2-butanone (84 g.), aluminum tri(isopro- I poxide) (78 g.) and isopropanol (382 cc.) was heated 0n working up as in Example 1, there was obtained 4-(2-methylr3-ethyl-5- isopropenyl-l-cyclopenten-1 yl)-2-butanol ,of B.P., 101- 103 (0.075 mm.); 11 1.4841. j

Example 7 By a procedure similar to that of Example 1, there was obtained from 4-(2-methyl-3-ethyl-5-isopropyl-1- cyclopentyl)-2-butanone (65.1 g.), aluminum tri(isopro'- poxide) (59.3 g.) and isopropanol (290 cc.), 4-(2-methyl- 3-ethyl-5-isopropyl-1-cyclopentyl)-2-butanol; B.P. 104- 106 (0.6 mm m, 1.4725.

Example 8 A mixture of 4-1Z-methyl-S-(4-methyl-2-penten-2-yl)- l cyclopenten-l-yll-2-butanone (416.2 g.), aluminum tri- (isopropoxide) (362.5 g.) and isopropanol (1775 cc.) was heated to boiling, and acetone produced during the reaction was eliminated by distillation. The mixture was worked up as described in Example 1, and 4-[2-methyl-5- (4 rriethyl-Z-penten-Z-yl)-1-cyclopenten-1-yl]-2-butanol was obtained; B.P. 109-110 (0.25 mm.); n 1.4818.

Example 9 In the manner described in Example 1, 4-[2-methyl-5- (4-methyl-2-pentyl)-1-cyclopentyl1-2-butanone (64.6 g.) was treated with aluminum tri(isopropoxide) (55.4 g.) and isopropanol (272 cc.) to produce 4-[2-methyl-5-(4- methyl-2-pentyl)-1-cyclopentyl]-2-butanol (56.3 g.); B.P. 110-111 0.6 mm); 1.4725.

vThe starting material for this example; i.e. 4-[2-methyl- 5 (4 methyl-Z-pentyl) l-cyclopentyll 2-butanone, B.P. 96 (0.4 mm.), n 1.4680; was made from 4-[2- methyl Q 5-(4-methyl-2-penten-2-yl) -1-cyclopenten-l-yl] Z-butanone, disclosed in Example 4 of above identified Patent No. 2,799,706, by catalytic hydrogenation at 125 C. and under 500 p.s.i. gauge hydrogen pressure in the presence of 5% Pd-CaCO catalyst, according to the process described in above identified U.S. Patent No. 2,- 849,490.

' t Example 10 To a mixture of 4-(2-methyl-5-isopropenyl-1-cyclopenten-I-yD-Z-butanol (50 g.) and dimethylaniline cc.) was added, at room temperature, a mixture of acetyl chloride 44 cc.) and acetic anhydride (27 cc.). Then, the reaction mixture was warmed to 40. for one hour, and allowed to stand at room temperature for two days. Finally, the reaction mixture was poured onto ice and water. 'Iheoil was separated, and was vwashed with dilute acid, with aqueous sodium bicarbonate solution,

and then with water until neutral. The product, 4-(2- methyl-S-isopropenyl-l-cyclopenten-l-yI)-2-butyl acetate, was purified by distillation in vacuo, B.P. 93-96 (1.5 mm.); r1 1.4675.

Example 11 4- (2,5 dimethyl-S-isopropenyl-l-cyclopenten-l-yl)- 2-butanol (59.7 g.) was added to a mixture of acetic anhydride (32.8 g.) and pyridine (64 cc.). The solution was heated to 80 for six hours, and then was allowed to stand overnight at room temperature. In the morning, it was poured cautiously onto 575 cc. of warm water. The oil was separated, and was washed to neutrality with dilute acid, sodium bicarbonate solution, and water. Vacuum distillation afforded 58.3 g. of 4-(2,5-dimethyl- 5-isopropenyl-l-cyclopenten-l-yl)-2-butyl acetate, B.P. 91 (0.8 mm.); n 1.4671.

Example 12 hours. It was allowed to stand overnight at room temperature, and then it was poured onto 1950 cc. of water.

mix re; s. x a d; i h t r... nd: h t e a e wa wa hed, eu r dr ed w h al um l ate-an isti d: rmethx t methy rzhpentemkyn- 5 clopenten-l-yll-Z-butyl formatewas obtainedat 106107 (0.8 mm.); n 1.4707.

Example 14 A mixture of.41[2-methyl-51(4rmethyl2gpentyl)-1-cyclopentyH-Z-butanol: (40.4.g.) andiforrnic acidi (46.5 g.) was heated to 80-85 for three hours.v Thereaction mixture was worked :up inthemanner described in Example 13, yielding4 .[2-methyl-51(4-methyl-2-pentyl)-1- cyclopentylLZ-butyl.formate; B.P. 103-105 (0.5 mm.); n 1.4607.

Example 15 Example 16 A, mixture of 4-(21rnethyl-3Fethyl-5risopropyl-l' cyclopentyl)-2 -butanol (43.9. g,, isobutyric anhydride (34.5 g.) and pyridine (43.5 cc.) was heated to 80 for six hours. Then, it was worked up in the manner described in Example 15, yielding 4-(2-methyl-3-ethyl-5-isopropyl- -l-cyclopentyl)2-butyl isobutyrate; B.P.= 112-115 (0.4 mm.); 11 5 1145-55 i Example.1.7

To a solution of 4.-(2;methyl-5 isopropenyl-lgcyclopennr- -y )-2;butano1, 0-4 n py dine g-l s add pw s'ewi h ir ng. be z y wchlq del t)- An exother rnic reaction ensued, causing a temperature rise to, 84. Then, heating, was continued for two hours at Q The m xtu ascoql d o oom. mpe ture a was poured Q to 1500 cc. of cold water. The oil was extracted with ether, and the ether layer was washed with saturated sodium bicarbonate solution and then with water until neutral. Finally, the. ether solution was dried with anhydrous calcium sulfate and distilled. The product, 4. .-.(2"- methyl S-isopropenyl-l-cyclopenten-l-yl)-2-butyl benzoate, was collected as a liquid at B.P. 132-133" (0.3 mm.) 1.5171. I

I claim: 1. A compound-having, the general formula 1 n-o-.-. -.o11,.-on,-on-lon -CH --CH= wherein the symbol X represents a tetravalent radical selected from the group consisting of the =CH-CH== radical and the =@C= radical; the symbol-Y represents a radical selected from the group consisting of' lower alkyl radicals and lower alkenyl radicals each containing'at least three carbon atoms and connected through the Z-carbon atom thereof; the symbol Z represents a member selected from the group consisting of hydrogen and hydrocarbylcarbonyl radicals which contain not more than seven carbon atoms in the hydrocarbyl 8 portion thereof; and each. of thesymbols R, R and R" represents a member selected from the group consisting of' hydrogen and lower acyclic hydrocarbonradicals.

2*. -4- [fl methyl-5-(2 lower alken-2-yl)-1 cyclopenten-1- ylJ -2-butanol. 3i Anester ofanalcohol according-- to claim 2 with an-"acid containing onlycarbon, hydrogen and oxygen atoms, the oxygen being only in the carboxy group of the acid and the acidcontaining not;more than eightcarbon atoms.

4. 4-E2-methy1-5-(2-lower alken-Z-yl)-1-cyc1openten 1- yl]-2-buty1-1ower alkanqate.

5. 4l2-methyl-5-( 2- lower alkyl) 1;cyclopenten-1-yl]-2- butanol.

6;;An ester of an alcohol according to claim 5 with an'acid containing only carbon, hydrogen and oxygen atoms, the. oxygen being only in the carboxy group of the acid and the acid containing not more than eight caron t ms I 7. 4- [2-methyl-5-(2-lowe r. allrylQ -l-cyclopenten-lryll-2- but l qwe kan e 8.' 4 2 niethylgS-(Z-lower alkyl)-1-cyclopenty1]-2- butanol. I

9, Anester of-an alcohol according to claim 8 with an acidcontaininglonly carbon, hydrogenand oxygen atoms, the. oxygen being only in the carboxy group of the acid and the acid containing not more than eight carbon atoms.

10. 4-[2-methyl-5-(2-lower alkyl)-l-cyclopentyl]-2-butyl lower alkanoate.

11. 4-(2-methyl 5 isopropenyl l-cyclopenten-1 y1)-2-butanol.

' 12. 4- (Lmethyl-jdsopropyl-l-cyclopenten-l-yl)-2-bu- References Citedin the-file of this patent UNITED STATES PATENTS 2,447,050 B ludworth,et a1. Aug. 17, 1948 55 5 l a n st t-t-a- June 5, 9 2,597,842 Linn May 27, 1952 ,59 ,8 3 L H i M 7. 1 52 OFEHER REFERENCES Muhlendyk, Chem. Abs. 8, 3184 (1914). Urion, Compt. rend. 194,.2311-3 (1932). Beilstein, Handbuch der Organischen Chemie, 4th Ed.,

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Chem. Soc. 74, 1909-12 1952 

1. A COMPOUND HAVING THE GENERAL FORMULA 